I. Field of the Invention
The present invention relates to a system for extending the effective operational range of an infrared remote control system of the type used with audio and video equipment.
II. Description of the Prior Art
There are many types of previously known remote controlled electronic devices which utilize an infrared signal between a remote control unit and the controlled device. Such controlled units include, for example, video cassette recorders, television sets, audio amplifiers, and the like.
One disadvantage of these previously known infrared remote control systems is that the operational range of the remote control unit is limited to a line of sight path between the infrared transmitter at the remote control unit and the infrared receiver at the controlled device. In many instances, however, it is highly desirable to operate the remote controlled device from more than one room.
One type of previously known device for allowing the controlled device to be operated from more than one room is disclosed in U.S. Pat. No. 4,509,211 which issued on Apr. 7, 1985 to Robbins. In the Robbins patent, the range for the infrared remote control system is effectively increased by utilizing a pair of transducer units which are electrically connected together by a wire transmission line. This previously known system, however, is disadvantageous since it is necessary to physically connect the transducer units together with a hard wire or transmission line. This oftentimes requires drilling holes in walls, floors, and the like.
An improvement over the Robbins patent is disclosed in my prior U.S. Pat. No. 4,809,359 which issued on Feb. 28, 1989. In my prior patent, a repeater was attached to the remote control unit which converted the infrared signal from the remote control unit to a radio signal. This radio signal was, in turn, received by a second repeater physically adjacent the controlled device. This second repeater reconverted the radio signal to an infrared transmission which was then transmitted to and received by the controlled device. Since the radio waves are capable of passing through walls, it was possible to operate the controlled device from a remote control unit that was not within the line of sight of the remote controlled device.
In operation, the first repeater of my device, i.e. the repeater which converted the infrared signal from the remote control unit into a radio signal, was contained within the housing which was then attached to the housing of the remote control unit. While this construction performed adequately, in some cases the extender housing became detached from the remote control unit and then became lost or misplaced. Furthermore, since there is little standardization of the physical shape of the housings for the infrared remote control units, it was necessary to design a different housing for the extender unit for different types of remote control units. This then increased the overall cost of production for my extender system.